This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-082832, filed Mar. 23, 2000, the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to an image processing technique applicable to, for example, a video game machine, and more specifically, to an image processing technique used to display, on a predetermined display device, a dynamic image including a background image showing a background scene and a character image displayed on the background image, which is an image of a particular character having in at least its part, a reflection portion on which the background is to be reflected.
2. Description of the Related Art
In an image processing apparatus applicable to, for example, a video game device, an background image of a certain background scene and a character image of a predetermined character to be displayed on the background scene are prepared, and a dynamic image synthesized by superimposing the latter on the former is displayed on a predetermined display device, thus making an entire scene, in many cases. Such background and character are selected appropriately in accordance with the contents of the game.
In the meantime, in the case where the character is, for example, a sphere having a surface processed into a mirror-finished, or a vehicle such as an automobile, there is, in some case, a reflection portion where the surrounding background is reflected in a part of the character. That is, in the case of the above-mentioned sphere, the whole outer surface serves as a reflection portion, and in the case of an automobile, the windows of the automobile, such as its front window and rear window are reflection portion.
In the case where a character image of a character having such a reflection portion is displayed on a display device, it is preferable as a matter of reality, that a character image of the character those reflection portion reflects the surrounding background image as it is so in reality, should be generated and displayed together with the background image on the display device.
However, it is excessively burdensome for an image processing apparatus to calculate one by one what sort of background image is reflected on a reflection portion, and thus determine an image to be reflected in the refection portion.
Therefore, conventionally, even in the case where a character having the above-explained reflection portion is to be displayed on a display device, such an image that reflects the surrounding background image is not shown in its reflection portion in many cases. Even if a certain reflection image is shown in the reflection portion, the best that can be done is a process that keeps on pasting a certain texture in the reflection portion at all times.
Although such a technique of pasting a predetermined texture selected from a plurality of types prepared in advance onto a reflection portion appropriately is used in order to emphasize the reality even for a little improvement of the scene, a smooth and natural motion cannot be expressed yet by with this technique and therefore it is not sufficient to pursue the reality.
The present invention has been proposed to solve the above-described drawback of the conventional technique, and its object is to provide an image processing technique capable of expressing a high-reality image in a reflection portion without applying an excessive load on the image processing apparatus device when a character having a reflection portion and a background scene are displayed on a display device.
In order to achieve the above-described object, the inventors of the present technique made intensive studies and have come to a technical conclusion that a highly real character image can be displayed at high efficiency if the background image is utilized since what is reflected on the reflection portion is a part of the background expressed by the background image present around the character image.
According to a first aspect of the present invention, there is provided an image processing method comprising the steps of: generating background image data of a background image; extracting part image data from the background image data, which corresponds to a part of the background image; generating base character image data of a desired character image including at least one reflection portion; generating composite character image data of the character image in which the part of the background image is pasted on the at least one reflection portion, using the base character image data and the extracted part image data; and generating dynamic image data according to the background image data and the composite character image data in order to display a dynamic image of the background image and the desired character image on a preset display.
There is a high possibility that what is displayed in the background scene image is originally reflected on the reflection portion. Therefore, the image expressed in the reflection portion by the method is highly real though it is not completely accurate. Further, the background image is originally necessary for displaying the dynamic image, and therefore if its part is cut out and pasted on some other part, which is a reflection portion, an excessive load is not created on the image processing apparatus by such an operation.
In the above-described method, the part of the background image is pasted on the reflection portion. Here, the part of the background image is directly pasted on the reflection portion as it is. It is further possible that the part of the background image is processed by vertical-to-horizontal-ratio conversion within such a range that it would not create an excessive load, and then the process part of the background image is pasted on the reflection portion.
It may be arranged that the composite character image data generating step includes a substep of executing at least one of coordinate inversion, brightness adjustment, and semitransparency processing, for the extracted part image data.
As the coordinate inversion is performed, it becomes difficult to recognize at sight that the image displayed in the reflection is simply a copy of the part of the background image, thereby improving its reality. As the brightness adjustment is performed, it becomes possible to improve the reality for displaying the reflecting image in the case of a reflection portion which has not very high reflectivity. As the semitransparency processing is performed, the reflection portion thus displayed shows a particular image drawn in advance to show its basic image of the original character is shown transparently under the part of the background image which shows the surrounding background, thereby achieving a high reality.
It may be arranged that the part of the background image positions above the desired character image on the displayed dynamic image.
It may be arranged that the desired character represents a three-dimensional shape, and the part of the background image positions in a direction of a normal vector of the at least one reflection portion.
It may be arranged that the desired character image includes a plurality of reflection portions, the part of the background image includes a plurality of sub-part images, and the composite character image data generating step generates composite character image data such that the plurality of sub-part images are pasted on the plurality of reflection portions respectively.
It may be arranged that the plurality of sub-part images may position above the plurality of reflection portions on the displayed dynamic image.
It may be arranged that the desired character represents a three-dimensional shape, and the plurality of sub-part images position in directions of normal vectors of the plurality of reflection portions respectively.
It may be arranged that a relative position relationship of the plurality of reflection portions coincides with a relative position relationship of the plurality of sub-part images on the displayed dynamic image.
It may be arranged that a correspondence between the plurality of reflection portions and the plurality of sub-part images is kept in accordance with a preset condition.
It may be arranged that the desired character image represents a vehicle.
It may be arranged that the vehicle includes a plurality of reflection portions, the part of the background image includes a plurality of sub-part images, and the composite character image data generating step generates composite character image data such that the plurality of sub-part images are pasted on the plurality of reflection portions respectively.
It may be arranged that the plurality of reflection portions correspond to windows of the vehicle.
It may be arranged that the windows comprise a front window, a rear window and left and right side windows.
It may be arranged that the plurality of sub-part images position above the plurality of reflection portions on the displayed dynamic image.
It may be arranged that the desired character represents a three-dimensional shape, and the plurality of sub-part images position in directions of normal vectors of the plurality of reflection portions respectively.
It may be arranged that a relative position relationship of the plurality of reflection portions coincides with a relative position relationship of the plurality of sub-part images on the displayed dynamic image.
It may be arranged that a correspondence between the plurality of reflection portions and the plurality of sub-part images is kept in accordance with a preset condition.
The correspondence between the plurality of reflection portions and the plurality of sub-part images may be set in any way. For example, the relative positions in the left-and-right direction of the sub-part images on the display device are made to match with the relative positions in the left-and-right direction of the sub-reflection portions on the display device.
More specifically, the sub-part image of the section situated on the leftmost side on the display device is pasted on the section situated on the leftmost one of the reflection portion, and then the rest of the sub-part images are pasted onto the rest of the reflection portions in the order such that the leftmost sub-image is pasted on the leftmost sub-reflection portion. With the above-described correspondence, when the background is displayed to show different portions on right and left directions on the display, the sub-part images pasted on the reflection portions do not very much part from reality. Thus, a dynamic image of a high reality can be achieved.
The correspondence between the plurality of reflection portions and the plurality of sub-part images can be kept at all times. With the above-described correspondence, a character image can be displayed at high reality, however when each time the character changes its direction, the positional correlations between the reflection portions change. Accordingly the relations between reflection portions and sub-part images change as well. It is laborious for the apparatus to grasp such a change in the correlations, and it may create an excessive load on the apparatus in some cases. In order to avoid this, the correlations between the reflection portions and the sub-part images are kept constant, thus making it possible to suppress the load on the apparatus to a very low level.
According to a second aspect of the present invention, there is provided an image processing apparatus comprising: a first generator for generating background image data of a background image; an extractor for extracting part image data from the background image data, which corresponds to a part of the background image; a second generator for generating base character image data of a desired character image including at least one reflection portion, and generating composite character image data of the character image in which the part of the background image is pasted on the at least one reflection portion, using the base character image data and the extracted part image data; and a third generator for generating dynamic image data according to the background image data and the composite character image data in order to display a dynamic image of the background image and the desired character image on a preset display.
According to a third aspect of the present invention, there is provided a storage medium having computer readable program code means embodied in the medium, the computer readable program code means comprising: computer readable program code means for generating background image data of a background image; computer readable program code means for extracting part image data from the background image data, which corresponds to a part of the background image; computer readable program code means for generating base character image data of a desired character image including at least one reflection portion; computer readable program code means for generating composite character image data of the character image in which the part of the background image is pasted on the at least one reflection portion, using the base character image data and the extracted part image data; and computer readable program code means for generating dynamic image data according to the background image data and the composite character image data in order to display a dynamic image of the background image and the desired character image on a preset display.
According to a fourth aspect of the present invention, there is provided a computer program operational on a computer, comprising the steps of: generating background image data of a background image; extracting part image data from the background image data, which corresponds to a part of the background image; generating base character image data of a desired character image including at least one reflection portion; generating composite character image data of the character image in which the part of the background image is pasted on the at least one reflection portion, using the base character image data and the extracted part image data; and generating dynamic image data according to the background image data and the composite character image data in order to display a dynamic image of the background image and the desired character image on a preset display.
It may be arranged that the computer program is stored in a computer readable storage medium.
It should be noted that the program of the present invention may contain, depending on the cases, data, parameters, etc. necessary for processing images, other than the program necessary to make the computer function as an image processing apparatus.